Stable operation of centrifugal compressors in gas turbine engines is limited by two forms of instabilities: rotating stall and surge. Both stall and surge can be detrimental not only to the performance of the compressor and its operability, but to its structural integrity as well. The diffuser of the compressor, and particularly the diffuser pipes, can contribute to these instabilities. Conventional passage control techniques for improving the stall range in diffuser pipes involve changing the throat size of the diffuser pipes, or performing overboard bleed. However, these solutions can require expensive hardware upgrades, modifications, or engine rematching.